Installation procedure for Fisheye/Crucible

We have JIRA up and running but when looking to add Fisheye/Crucible addons the documentation is very confusing and not clear which should be installed and in what order. Also, there is no indication whether Crucible is just a more feature rich version of Fisheye or a separate addon. Each references the other and there is no clear indication which is necessary and what order they should be installed (FYI - Windows x64 install). Please help clarify.